Electrical resistor



W. HGOPES.

ELECTRICAL RESISTOR APPLiC/(T'ION FILED 0612. 1919.

Patented Oct. 11, 1921.

ope-a material, preferably of copper,

, tion of nrrn 'WXLLEAIMI HOUPES, 333" OF IEPENIISYLVAN sre'ras rnre'r ounce.

T 3 ALUMINUM 'UORPORATION ILL UR ELECTRICAL REQ'ESTOR.

To all 107mm 2'1? may concern:

it known that l, lVILZJIAM Hoorns, a citizen oi the United States oi America, and a resident of Pittsbur h, in the county oi Allegheny and otate or i ennsylvania, have invented an Improvement 1n Electrical liesistors, of which the following -le cription, 1n COllIlQClZlOIl with the accompany ng drawings, 15: a specification, like characters on the drawings re resenting'lllce parts.

This invention relates to electrical sisters. p

lhe invention and its aims and ob ects will be best understood from the following description, taken in connection with the ac conipanying drawings, of a resistor con struction embodying one form-of said in vention selected for purposes of illustration, it being understood hat the invention in its true scope is definitely set forth by the appended claims.

In the drawings: l1 igure 1 is an elevation of one illustrative form of resistor or resistor certain features of my invention; i

'Fig. 2 shows a vertical longitudinal secthe illustrative form of resistor shown in Fig. 1: with an illustrative form of means according to my invention for maintaining electrical contact said contact is liable to become impaired in use; and

Fig. 3 is a detail of the lower the tube 8 and pipe 12., and the casting 10."

In accordance with my invention the re sistor may comprise any desired number of resistor elements. Referring; to the draw: ings, the resistor therein shown comprises a series of eight such resistorelements 2,placed inline and each in eledtrieel contact with the one next to it. A member of electrically conductive material, herein exemplified by a larbon block 4%, will. preferably he placed in contact with the resistor element at one end of the series, and another such carhon block 6 in contact with the resisto element at the other end of the series, these blocks 4 and 6 thus constitutingWhat may conveniently be termed the contact electrodes.

An electrical conductor 8 of any suitable and in the illustrative embodiment of the invention herein showmextending longitudinally of the series of resistor elements 2, has one end adapted. to be connected to one terminal of the electric circuit by which' the resistor is Specification. of Letters Patent.

Application filed may 2, 1919..

unit embodying V of the parts Where its inner end portion of -jects from the free end of the Patented Oct. iii, 1921. serial no. 3211,9551.

to be suppliedwith current, while the other end of said conductor is electrically connected by any suitable means to the resistor element at one end of the series While being maintained out of contact with the others. y connecting the resistor element at the other end of the series of said elements with the other terminal of the electric circuit serving to supply current to the resistor, current may be passed through the letter;

In the illustrative embodiment of the invention herein shown, the conductor 8 extends substantially axially through the selies of resistor elements 2 and through the carbon blocks 4 and 6. I may use any suit-- able means for establishing electrical con- .tact between the conductor 8 end-the resistor in any suitable manner against the end face of the extending substantially azgi ally through the tube-.8 and havingi the casting 10;,

opening into provided with an interior chamber 14. The tube .8 surrounding the pipe 12 is preferably screw threaded eXtei-iorly atits inner end threaded which latter is screwed into a screw opening extendmgthrough the wall of said" casting 10. The pipe 12 is of smaller ex terior cross section than the interior cross section. or the tube 8, and at its free end procopper tube A pipe end of the tube 8, to I 'which it is sealed at 16 in any, suitable man ner to form a fluid tight junction. The free end of the tubeB terminates in an I 18 into. which is screwed an overflow pipe 20. The free end of the pipe 12 is connected by any appropriate connection to any suitable source of suply, not shown, of water or other fluid cooling agentpreferahly under pressure. 1 preferably use Water, the supply of Water to the pipe 12 being controlled by any suitable means, such as a valve Cold Water may thus be admitted into the pipe 12 through which it passes downward into the hollow copper casting 10 and thence upward through the annular space between the" pipe 12 and tube 8: whence it is discharged through the overflow pipe 20. It is thus possible continually to maintain the conductor 8 and the other above described metal parts at temperatures below the liioiling point of water, irrespective of how much heat they may be subjected to on the outside. Efficient cooling means is thus provided for the conductor 8 and other metal parts de scribed, whereby overheating thereof prevented.

In order to intercept as much heat as possible, i may, however, provide additional means to that effect. In the illustrative embodiment of the invention herein shown, said heat ii'itercepting or insulating means may conveniently comprise the following instruinentalities.

Upon the lower end or": the tube fitted a block 241 of any suitable heat-insulating and electrically non-conductive material, such as aluminum nitrid for example. This block rests upon the upper surface of the I casting 10 and Will preferably be of an er:-

terior crosssection somewhat less than the cross-section of the axial opening provided in the carbon block 4:. Upon said block :24- rest end to end a series of sleeves 26, pret erably of graphite, said sleeves surrounding the tube 8 and having an interior diameter greater than the exterior diameter of said tube 8 and an exterior diameter preferably smaller than the interior diameter of the resistor elements 2. The sleeves 26 are preferably separated from each other by separating blocks 28 fitted upon the tube 8 and made of any suitable electrical and heat-insulating material. These blocks 28 serve to keep the graphite sleeves 26 properly spaced from the tube 8 and electrically ins sated from each other for a. purpose hereinafter more full described. The annular space between the sleeves 26 and the tube 8 will preferably be filled in With suitable heatinsulating material 30 of high heat-resisting properties. Powdered alumina, powdered magnesia or any other welldrnown electrically non-conductive powdered material may he used for this purpose. The annular space between the interior wall of the carbon block land the outer Wall of the block 24 may also be filled in with this or a. similar heat-insulating material.

It will be apparent to those skilled in the art that the heat which would otherwise pass inward from the resistor elements 2 to. the \VieiGT-COOlGCl conductor 8 will be mostly intercepted by the layer of high heat resisting material, whereby the amount of heat passing into the cooling Water will be reduced to a minimum.

The proper composition of the blocks 28 is dependent upon tle purpose for which the resistor unit is to be used and the temperature to which it is to be subjected. For

1 ,eoasva a temperature of 1800 C. or over I preferably make these blocks of aluminum nitrid of high purity, as this compound possesses a higher resistance to high temperatures than any other commerciall available material known to me, but any other suitable mate rial having the necessary high coefiicient of heat resistance may be used. For lower temperatures other less expensive refractory materials may be employed.

Over the Water-cooled casting in there will preteraoly be placed a rap or covering of .heat-insulating material 32 to prevent influx of heat into this casting. 1 preferably use for this purpose a cap of carbon secured to said casting in any suitable manner.

The resistor or resistor unit shown in Fig. 1 is complete and-ready for use in connection with any suitable form of apparatus, which. latter will of course vary according to the purpose for Whici the resistor is to be used. In. use the current passes inward through the tube 8 into the Water-cooled casting'lO, thence into the carbon block l and thence into the end resistor element 2 in contact with said block 4 and soon through the entire series of resistor elements into the carbon block 6 at the other end of rid serie On account or the relatively high conductivity of the copper conductor 8 and copper casting l0, and the fact that theseare cooled, it is possible to lead current through said conductor in suliiciently large quantities to heat the resistor to high temperatures.

It will be apparent to those skilled in the art that my invention is not limited to resistors of any particular term or type, but is applicable to resistors i n. general. The invention is very useful in practicing proceases involving chemical reactions Where the heat necessary to the reaction is supplied by electrical energy, on the resistance principle of heating, the charge itself constituting a resistor Within which the heat necessary for the reaction is thus developed.- lVhere my invention is applied to this use the resistor elements 2 will consist of self-sustaining liloelrs containing the ingredients that are to take part in the reaction. Thus, in the application of the invention to the nitrification of charges consisting of aluminous material the resistor elements 2 constitute the charge and will comprise a mixture of any suitable alumiuous material, a suitable carhonaceous material, such ascoke or coal, for example, to act as reducing agent, and a suitable binder. I preferably use for this purpose a mixture comprising powdered bauxite, coke and tar in the proportions of about 50 pounds of. powdered bauxite, about 25 pounds of coke and about 25 pounds of tar. These ingredients having been thoroughl mixed, the mixture is formed into the current passes through the graphite studs 46, 46 to the water cooled casting 3.) and thus to the other terminal oi the circuit. A. thin layer of mercury 56 will preferably be provided within the cylinder 35 to pert'ect the electric contact between the piston 36 and said cylinder.

Air, or any other suitable medium, from any suitable source of supply under pressure, not shown, is admitted into the cylinder between the piston and, the cylinder'hcad 40 through a pipe 58, the admission being controlled by any suitable means such as a valve 60 provided in said pipe. As the blocks shrink duringthe progress of the nitrification or other chemical process, the air pressure thus acting upon the piston within the cylinder will exert sufhcient stress upon the tube or conductor 8 to maintain all the resistor elements of the resistor unit in firm electrical contact with each other and with the carbon blocks 4 and 6 and the latter in firm contact with the graphite slab 4d. The electric circuit will thus be kept complete at all times in spite of any shrinkage that may occur in the resistor. 1

lVhen the above described shrinkage takes place it does not always take place uni- .t'ormly, so there may be a-tendency of the resistor to warp out of a stranrht line. The

resistor is kept from collapsing in such case by reason of the fact that such warping is arrested as soon as the resistor elements come in contact with the graphite sleeves 26. The latter are electrically sectionalized by the insulating: blocks 28 for the purpose of preventing current from passing endwise through said graphite sleeves, in case such accidental contacts should occur.

It will be apparent to those skilled in the art that resistors embodying my invention I possess many advantages over resistors heretofore used. Thus, a resistor embodying my invention may be placedv and will function in any position best suited for the purpose for which it is used. -Fer example it may be entirely suspended from above so as to hang naturally in a vert cal position below the point of support. 1ers a plurality of the units are used, each one may thus be suspended out of contact gWltll the others so that each vone will be completely insulated electrically from each of the others. They may thus be suspended out of contact With the walls of the apparatus in which they are used. This is peculiarly advantageous Where the resistor elements consist of blocks for carrying out chemical reactions, and more particularly for carrying out chemical reactions between solid and gaseous bodies, as free access Will thus be given the gas to all sides of the block. On account of the fact that each unit may thus be isolated, it is possible and evendesirable to supply each unlt With current from an int cpendent source, so that the amount of energy delivered to each unitis independent of the amount delivered to any other. The electric circuit is maintained at all times in spite of any possible shrinkage or displacement oi? the resistor elements by reason of the chemical reaction occurring therein or for any other reason and collapsing of the column due to possible warping or any other cause is also prevented as already fully explained.

It will also be noted that connection with the two terminals of the circuit supplying current to the resistor may be made at substantially the same point, adjacent one end of the resistor for example. \Vhen the resistor is suspended or otherwise disposed with one end at or near the upper or open end of a furnace or other apparatus, connection with both terminals of the supply circuit may thus be made at said upper or said open end, thus greatly facilitating the making of said connections.

Other advantages secured by my invention, in addition to those herein specifically pointed out, will appear to those skilled in the art.

It will be understood that, while the invention is herein described as embodied in the details illustrated, the invention is not to be considered as circumscribed by or limited to these details or any of them, but that said details may be variously modified within the true scope of the invention which is ,definitely set forth by the claims. It will hemnderstood also that it is not indispensible that all the features of the invention be used conjointly, since they may be used to advantage separately in various combinations and sub-combinations, as defined in the subjoined claims.

Claims 1. In combination, an electrical resistor; an electrical conductor electrically connected to one end of said resistor and extending subtantially axially thereof but not electri cally connected to the other end of said resistor; means for connecting said conductor to one terminal of an electric circuit; and means for connecting the other end of said resistor to the other terminal of said circuit.

2. In combination, an electrical resistor; an electrical conductor electrically connected to one end of said resistor; fluid cooling means for said conductor 'eilective coextensivelywith the resistor; means for connecting said conductor to one terminal of an electric circuit; and means for. connecting" the other end of said resistor to the other terminal of said circuit.

3. In combination, an electrical resistor; an electrical conductor extending substantially axially of the resistor and electrically connected to one end of said resistor; heatinsulating means for said conductor exterior masses v {Tm-said condoctor; means for connecting said conductor to one terminal oi an electric circuit; and insane for connecting the other end of said resistor to the other terminal of said circuit.

.i. In combination, an electrical resistor; an electrical conductor; and means oper ative throughout said resistor to prevent overheating of said conductor.

5. in combination, an electrical resistor comprising a plurality of resistor elements forming part of an electric circuit; and means to maintain the continuity of said electric circuit through said resistor lements.

6. in combination, an electrical resistor comprised of an electric circuit; and means to maintain. the continuity of the circuit through said resistor.

7. in combination, an electrical resistor; an electrical conductor electrically connect-- ed to one end of said resistor; means for conmeeting said conductor to'one terminal of an electric circuit; means for connecting the other end of the resistor to the terminal ofsaid circuit; and means to preserve the continuity of. said electric circuit through said resistor.

8. ln coniliinatirni an electrical resistor; means. abutting against one end of said resister; means abutting against the other end of said resistor; an electrical conductor connected to one oi id abutting nieans but disconnected from the other; and means to exert stress upon said conductor to inanitainelectrical contact between said resistor and said abutting means,

9 In COHllJlRELlJIOII, an electrical resistor comprising a plurality of resistor elements;

I means abutting against one end of said re sister; means abutting against the other end of said resistor; an electrical conductor connected to one of said abutting means lout dis-- connected from the other; and means to caert stress upon said conductor to maintain electrical contact between said resistor elements and between said resistor and said abutting means.

10. In combination, an electrical resistor; an electrical conductor electrically connected to one end of the latter; means electrically connecting the other end or" said resister to one terminal of an electric circuit; means electrically connecting said conductor to the other terminal of said circuit; and means to suspend said resistor by said conductom ll. In combination, an electrical resistor comprising one or more resistor blocks con taimng materials for carrying; out cliemical reaction; an electrical conductor extending lengthwise of said resistor and. electrisally connected at one end to one end of said resistor; means for connecting the other end agent and a binder;

of said. conductor to one terminal of an electric circuit; and. means for connecting the other end of said resistor to the other terminal of said circuit 12.111 combination, on electrical resistor comprising one or more resistor blocks containing' materials for carrying out a chemrcal reaction; an electrical conductor extencllog; lengthwise of said resistor and electrically connected at one end to one end of said resistor; cooling means for said con (luctor; of said conductor to one terminal or an electric circuit; and means for connecting the other end of said resistor to the other terminal of said circuit.

13. lo combination, an electrical resistor comprising one or more resistor blocks con taining materials for carrying out a cherrical reaction; an electrical conductor extending lengthwise of the resistor electrically connected at one end to one end. of said resistor; heat insulating means for said. (301% doctor; means for connecting the other end of said conductor to one terminal oi? an electric circuit; and means for connecting the other end of said resistor to the other terini rial of said circuit.

i l. In combination, an electrical resistor comprising one or more resistor blocks containing materials for carrying out a chemical reaction; an electrical conductor extend inc; lengthwise of the resistor and electrically connected at one end. to one end of said resistor; means for connecting the other end 1" said conductor to one terminal of an electric circuit; means for connecting the other end of said resistor to the other terminal of said circuit; and means to preserve the con tinuity of said circuit through said resistor.

l5. In combination, aresistor comprising one or more porous resistor blocks provided with a gas passage and containing a mixture of an aliuninous material, a reducing means to admit gas to said electrical conductor electrically connected to one end of said. resister; means for connecting said conductor one terminal of. an electric circuit; and. means for connecting the other end of said resistor to the other terminal of said circuit.

16. In combination, a resistor comprising one or more porous resistor blocks provided with a gas passage and containing a mixture of an aluminous material, a reducing agent and a binder; means to admit gas to said gas passag-i' electrical conductor electrically connected to one end of said re sister; cooling means for said conductor; means for connecting said conductor to one terminal of an electric circuit; and means for connecting the other one of said resister to the other terminal of said circuit.

1'7. In combination, a resistor comprising one or more porous resistor blocks provided means for connecting the other end with a gas passage and containing a mix-- ture of an aluminous material, a reducing agent and a binder; means to admit gas to said passage; an electrical conductor electrically connected to one erul. of said resistor; heat insulating means for said con ductor; means for connecting said conductor to one terminal of an electric circuit; and means forconnecting the other end of said resistor to the other terminal of said circuit. 18. lo combination, a resistor comprising one or more porous resistor blocks provided with a gas passage and containing a miss ture of an aluminous material a reducing agent and a binder; means to admit gas to said gas passage; an electrical conductor electrically connected to one and of said resistor; means for connecting said conductor to one terminal of an electric circuit: In =ans for connecting the other end or said rc sistor to the other terminal of said circuit: and means to preserve the continuity of said circuit through said resistor.

if? in combination, an electrical res adapted to be connected at one and to all electric circuit; and an electrical conductor clectrically connected to the other end or said res tor and adapted to he connectcd to said electric circuit, adjacent the end of the resistor that is cmnicctcd to said circuit, said conductor being; within said resistor.

20 In combination. an electrical resistor adapted to be connected at one end to one terminal of an electric circuit: an electrical conducl'w within said resistor and electrically connected to tho other and of the latter; said coinluctor being); ada 'itcd to lac conncctcd to the other terminal of said elcctric circuit: and cooling means for said conductor.

21. in comliinal'imi. an electrical resistinadapted to be connected at one end to an electric circuit: an electrical conductor \\llllill said resistor and clcclricallv coir ucrlcd to the other end of the latter. said conductor being adapted to l)( connected to said clcctric circuit :uljaccnl' the cod or the resistor that is connccl'cd to said circuit: and iusulalin; mcans for said coiulucl'or.

ln combination. anelcctrical resL tor adap ed to be connected at one end to an clcclric circuit: an electrical conductor \\'1ll Hll said rcsistor and electrically connected to the other end of the latten said conductor being: adapted to be connected to said electric circuit adjacent the cod ol' the resistor that is connected to said circuit: and means to prcscrrc the continuity of said electric circuit through said resistor.

23. in combination an electrical resistor; abutting means for one end ol said resistor: abutting" means. for the other and (ii said resistor; an electrical conductor extending;

axially of said resisto' and connected to one in;

{if said. abutting means but disconnected from the other: and means to exert stress placed cud to end; abutting means for one end of said resistor; abutting means for the other end oi said resistor; 21 coni'luctor pipe ntending axially or said resistc and connected to one oi said abutting means but disconnect er from the other; mcans to exert stress upon said conductor pipe to maintain electrical contact between the various clcmcnlis oi said resistor and said resistor and said abutting: means: and means for supply ll a currcni: or" cooling fluid through said cmnluctor pipe.

"3. in combination. an electrical resistor "cmprisinn a plurality o'l res" :or elements Jlaced end in end; aln .i means for one cud of said resistor; abutting means For the other erul oi said resistor; a conductor pipe exit-ruling axially of said resistor and con neclcd to one of said abutting means but disconnected from the other; a cylinder: a pis ton in said cylinder connected to said con ductor pipe: and means for supplying a pressure medium to said c \'lindcr at one side ot' the piston to exert stress upon said conducto pipe for the purpose of maintaining: clicl ical contact between the several elements of said resistor and between the resisl'or and said abutting means.

2?. in combination. an electrical resistor comprising a plurality of resistor elements placed cud to end: abuttingmeans for one cnd of said resistor; abutting means for the other end of said resistor: a conductor pipe extending axially of said resistor and connected to our ol said abuttingmeans but discouncctcd from the other: a r vlinder; a piston in said cylinder connected to said eonductor pipe: means l'or supplying a pressure medium to said cylinder at one side of the piston to exert stress upon said conductor pipc for the purpose of maintaining electrical contact betwccn the several, elements of said resistor and between the resistor and said abutting means: and means for supplymgn current of cooling; lluid through said. conductor pipe. i

in testimony whereof, have signed my run.

Lian acorns Sil 

